Neurologists paint bleak Leqembi launch picture as Alzheimer's drug trips up on a host of challenges

It wasn’t supposed to be like this: Eisai and Biogen’s new Alzheimer’s disease drug Leqembi was supposed to be the chosen one after the flop that was Biogen and Eisai’s Aduhelm, but neurologists are voicing “frustration” at core elements of the therapy’s rollout.

That’s according to a stark new report out by life sciences consultants at Spherix that delved down into insights from 75 high-prescribing U.S. neurologists that work with Alzheimer’s patients.

The picture painted by them is bleak: Now around six months after the launch of Leqembi, “few surveyed neurologists consider Leqembi to be a significant medical advance over other historical AD treatments,” Spherix’s analysis found.

It also found that satisfaction with Leqembi “is relatively low,” with the average satisfaction rating being a full 15% lower than the typical rating for a new neurology market entrant, the consultants said.

“Perhaps related to that, less than half of neurologists surveyed are actively recommending Leqembi to patients,” the report found.

In its most recent third-quarter results report, Leqembi generated just 1.1 billion Japanese yen in U.S. sales (equivalent to around $7.4 million) during that three-month period.

Eisai had set the goal to reach 10,000 patients with Leqembi by the end of its 2024 fiscal year, which wraps up in March, but only 2,000 patients in the U.S. were receiving the amyloid-busting antibody as of Jan. 26, Eisai said during its third-quarter earnings presentation earlier this month.

Spherix regularly interviews prescribers for these reports, and one anonymous neurologist summed up the issue: “I present the facts. In the end, what I tell them is I am not enthusiastic about using the drug. I never tell patients that it’s wrong for them to choose Leqembi. I just tell them that I don’t believe that it’s as helpful as they might have heard about, read about or, what they’ve discussed with other friends or family.” 

That’s not all. There are also some deep issues over coverage, testing and the logistics of getting the therapy. On the coverage side, while the Centers for Medicare & Medicaid Services will cover Leqembi, getting Medicare coverage for patients is in reality “posing a challenge,” the neurologists told Spherix.

The report notes that, on average, two-fifths of patients who should be eligible were not in fact prescribed Leqembi because they could not obtain Medicare or other insurance approvals. For others, the copays were simply too high.

Leqembi works by removing beta amyloid in the brain, one central theory as to what causes Alzheimer's. To get the drug, you need to be tested and shown to have beta amyloid, but nearly half of those 75 neurologists surveyed by Spherix have reported issues with conducting the right sort of amyloid testing to get the go-ahead to use the drug.

Safety testing is also an issue. Amyloid related imaging abnormalities (ARIA) can be a serious complication of using Leqembi, and, while there is a monitoring test for ARIA, one-third of those asked also had issues with this safety test for the drug.

Finally, on the logistics side, getting the drug into patients is also proving a stumbling block. Leqembi needs to be infused at a specialist center, but three-fifths of patients, according to the report, are having their treatment at an off-site infusion center that is unrelated to the neurologists’ practice.

Neurologists are, however, optimistic about one potential future Alzheimer's drug, which will work in a similar way to Leqembi, in the form of Eli Lilly’s donanemab. This drug, which could see an approval this quarter, may have an edge over Leqembi.

Back in May 2023, donanemab achieved a 35% slowing of cognitive decline and a 39% lower risk of advancing to the next stage of the disease, when compared to placebo.

Compare this to Leqembi, which, in its data posted a few years ago, demonstrated a 27% reduction in cognitive decline compared to a placebo. There are key differences between the studies, and the normal warning around making direct comparisons remains—but Lilly said last year that donanemab has set a new standard.

However, Donanemab still carries a risk of ARIA and, much like Leqembi, may encounter similar testing, coverage and logistical challenges if approved, akin to those currently facing Eisai.

In their recent report, analysts at Evaluate projected that Leqembi is expected to generate approximately $3 billion by 2028, while estimates for donanemab hover around $2.2 billion by the same date.